Photographic print drier



N. W. DAVIS ETAL PHOTOGRAPHIC PRINT DRIER Dec. 13, 1960 2 Sheefs-Sheet 1 Filed Dec. 4. 1957 NORMAN n. DAV/S EDWARD L. KERR lNVEN ORS WZ Z A, ATTORNEYS United States Patent PHOTOGRAPHIC PRINT DRIER Norman W. Davis and Edward L. Kerr, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Dec. 4, 1957, Ser. No. 700,694

3 Claims. (Cl. 257-95) The present invention relates to driers of the drum The prior art shows photographic print driers in which the print is pressed onto the polished periphery of a rotating heated drum during a portion of a complete rotation thereof. Such drums have been heated in a number of ways, i.e., by the use of gas, electricity, hot water, steam, etc., but the use of a heated fluid such as water or steam has generally proved most economical and satisfactory. In order to reduce the amount of fluid which has to be heated and to get the most immediate and eflicient heat transfer to the periphery of the drum where it is needed, it has been common practice to provide a rather shallow water jacket immediately adjacent the periphery of the drum, and one wall of which is formed by the drum periphery, through which the heated water is continuously circulated. The periphery of these drying drums must be highly polished and this requires that from time to time they must be refinished. Likewise, it may be necessary from time to time to clean sediment or scale from the interior of the water jacket in order to obtain the most efiicient heat transfer. With known drum driers these operations have required a tearing down of the over-all apparatus to remove the entire drum for refinishing of its periphery and a shutdown of the apparatus during this time.

One object of the present invention is to provide a drum drier of the type described which is so constructed thatthe periphery of the drying drum constitutes a separate cylindrical rim which can be readily slipped onto and off the drum proper for easy refinishing of its surface and/or cleaning of the water jacket, one wall of which is formed thereby. This construction not only results in a cheaper'initial construction of the drum but allows continued use of the over-all apparatus during the time the surface of one drum is being refinished by replacing it with a spare.

Another object is to provide a drying drum of the type disclosed in which the drying surface of the drum comprises a cylindrical rim of slightly larger outside diameter than the drum proper and which is held in concentric relation on the drum periphery by radial partitions adjacent each end of the drum, said partitions, rim and drum periphery forming a shallow water jacket extending completely around the drum.

A further object is to provide a liquid-tight seal for the ends of said water jacket which permits the rim to he slipped onto and off the end of the drum as desired, said seal including a pair of inflatable rubber-like tubes encircling opposite ends of the drum and, when inflated, contacting both the periphery of the drum and the inner surface of the cylindrical rim. These tubes when inflated also serve to frictionally connect the rim to the drum, so that it rotates with the drum as the latter is driven.-

Another object is to mount the drum on a supporting" ICC 2 frame at one end only in cantilever fashion and leaving the side of the frame adjacent the unsupported end of the drum open so that the cylindrical rim can be readily slipped onto and off the drum and the strip of prints to be dried can be readily threaded about the drum from the end thereof.

The novel features that we consider characteristic of our invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof will best be understood from the following description when read in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view of a print drier constructed in accordance with a preferred embodiment of our invention and shown as being used to dry two long strips of photographic prints;

Fig. 2 is a vertical section taken substantially through thehub of the drier drum and looking from the takeup end of the apparatus shown in Fig. 1; and

Fig. 3 is an enlarged sectional detail at the water-tight seal at one edge of the drum.

Generally speaking, the present drier comprises a rotatable drum which is so constructed that the rim thereof can be slipped onto and off the end of the drum. The rim has an internal diameter greater than the outside diameter of the drum proper and is held in concentric relation on the drum by radial partitions adjacentthe ends of the drum so that the space enclosed by the rim, the drum periphery and these partitions form a shallow water jacket around the drum through which temperature-controlled water, or other fluid, is circulated to heat the I'll'IL' Water-tight seals for the ends of the water jacket are formed by inflatable rubber-like tubes. These tubes when inflated also serve to frictionally connect the rim to the drum so that it will rotate therewith. The drum is mouned on a supporting frame in cantilever fashion and the frame is left open at the unsupported side of the drum to make it easy to slip the rim onto and on the drum and to facilitate threading the drum with a strip of prints to be dried.

Referring now to the drawings, the apparatus comprisesa box-like supporting frame 10, the front side, that facing forward in Fig. 1, of which is completely open and the rear side of which has two parallel cross bars 11 closing it, see Fig. 2. Fixed to these cross bars 11 by welding, or other suitable means, is a bearing support 12 in which bearings 13 are mounted in axially spaced relation. These bearings serve to rotatably support in cantilever fashionthe hollow shaft 14 of a drying drum, indicated generally at 15, so that the unsupported end of the drum faces the open side of the supporting frame to permitready removal of the drum rim and threading of the drum as will be hereinafter set forth. The hollow shaft 14 and the drum thereon is driven through a sprocket 16 fixed to the shaft and engaged by a chain 17 which in turn engages a sprocket 18 forming a part of. a motor and gear reducer set M mounted on;a.hor iz0nta1 plate 19 fixed to the frame 10.

In accordance with the present invention, the drying drum comprises a drum proper 20 connected to the hollow shaft v14 by radial supporting webs or spokes 21 which are welded to the shaft and fixed to the drum periphery by bolts 22 engaging lugs 23 fixed to the inside of the drum. Fixed to, and extending radially from, the periphery of the drum adjacent each of its ends are a pair of partitions 25 and 26 which form a trough or groove"27extending circumferentially around each end of the drum. As clearly shown in Fig. 3, these partitions"'- 2 5 and 26 may comprise a pair of rings 28 and 29 having an L-shaped cross section, one of the arms of each ring,'30of ring" 28 and 30" of ring 29, engaging Patented Dec. 13, 1960' and being fixed to the periphery of the drum, while the other arm of each ring forms the radially extending partitions 25 and 26 mentioned above. The outside surface of the drum comprises a chrome-plated copper cylindrical rim 32 having an internal diameter slightly greater than the outside diameter of the drum proper and substantially equal to the diameter of rings 28 and 29 so that the rim may be slid onto and off the drum from the unsupported end thereof. When the rim is in position on the drum, it is supported in concentric relation with the drum periphery by partitions 25 and 26 to form with said partitions and the drum periphery a shallow water or steam jacket 33 which extends completely around the drum.

A liquid-tight seal for this water jacket 33 is formed by an inflatable rubber-like tube 34, similar to a tube for a bicycle tire, which surrounds the drum and lies in the trough 27 formed by each of partitions 25 and 26. Each of these tubes has a valve stem 35 extending through a hole in the drum periphery, see Fig. 3, to permit selective inflation and deflation of said tubes. When these tubes are deflated, the rim 32 can be readily slid otf the unsupported end of the drum for any reason, i.e., refinishing of its polished surface, cleaning the water jacket, etc. When the rim 32 is slipped back onto the drum and the tubes are sufliciently inflated, they are expanded into contact with both the periphery of the drum and the rim to form a liquid-tight seal for the ends of the water jacket. In addition, these tubes 34 also serve to frictionally connect the rim to the drum so that it wil rotate therewith, and they thus eliminate the need for any separate releasable fastening means between the rim and the drum. It is because of this last-mentioned function of the tubes that they should be made of a rubber-like material which has a relatively high friction coefficient rather than being formed of a slippery material. 'It is pointed out that the radial partitions 25 and 26, in addition to serving to support the rim in concentric relation with the drum periphery, also serve to keep the tubes 34 from being pulled off or displaced inwardly of the drum as the rim is slipped off and onto the same. In addition, these partitions confine the lateral expansion of the tubes as they are inflated and compel them to expand in a radial direction so as to produce the desired sealing and frictional contact between the drum and rim surface. While it may be preferable to fix the partitions 25 and 26 to the periphery of the drum as shown, it is within the scope of the invention to have the partitions, or their equivalent, fixed to the inside of the rim, in which case the partition and tubes confined thereby will be removed from the drum with the rim. The front and rear ends of the drum may be enclosed by cover disks 41 and 40, respectively. The rear cover disk 40 may be permanently attached to the drum in any suitable manner since it need not be removed, but since the front cover disk 41 has to be removed from time to time, some suitable detaching means should be provided for this cover. One suitable means is shown which comprises providing a plurality of turned-in lugs 43 on the ring 29 having tapped holes into which screws 44 passing through the holes in the disk 41 may be threaded, see Fig. 3.

As is well known in the art, the rim 32 is heated by continuously cilculating a temperature-controlled fluid, water, steam, etc. through the water jacket 33. In our apparatus water is used as the heating medium and the pump for the water and the thermostatically controlled heater for the water are both mounted within the drum and rotate therewith, both the electrical and water services being supplied through the hollow drum shaft 14, as will now be described. Looking at Fig. 2, water is fed into a motor driven pump, indicated generally at P,

through a pipe 50 which passes through the hollow shaft 14. Since the pump is supported within the drum so as to rotate therewith, the pipe 50 must also rotate with the drum and a well-known type of liquid seal 51 is provided between the pipe 50 and the stationary pipe 52 to allow for this rotation. The discharge side of the pump P is connected to a pipe 53 whichaconnects to a T section 54 so that water is fed into the jacket 33 at two separated points 55 and 56. The intake side of the pump is connected at one point 57 to the water jacket 33, said point being substantially 180 degrees from the discharge points 55 and 56 by a pipe 58 which includes a conventional electric heater indicated at 59 and which includes a conventional thermostat control 60 having a setting dial 61 accessible from the outside of cover disk 41. A thermometer T extending through cover disk 41, see Fig. 1, will indicate the temperature of the water in the discharge side of the system and which temperature may be different from the actual thermostat setting due to temperature losses in the system. The water pumping system shown here is a closed system comparable to that used in automobile engines, and after the system is once filled, the supply system, including pipe 50, stationary pipe 52 and expansion chamber 63, merely takes care of expansion of the water in the system as it is heated. In order to bleed air from the system during a filling operation, the water jacket 33 may be provided with a petcock 65.

Electrical service to the rotating electrical heater and pump motor is transmitted through the use of collector rings and brushes as will now be described. Looking at Fig. 2, fixed to the hollow shaft 14 outside the drum is a hub 66 made of some insulating material, such as a phenolic, and having a raised separating rib 67 extending around the center thereof. Fixed to the hub on opposite sides of the separating rib are two collector rings 68 and 69 which are engaged by brushes 70 and 71 carried by an insulating block 72. Opposite ones of these brushes are connected to different ones of electrical supply leads 73 and 74. Opposite ones of the collector rings 63 and 69 have connected thereto insulated wires 75 and 76 which extend through a hole in the shaft 14 and then axially through the shaft and to the pump motor and electrical heater as shown.

In Fig. 1 we have shownthe drier drum as drying long strips of photographic prints as they are puled from reels on which they were processed, but it will be appreciated that the drier could take strips of prints directly from a continuous processing machine as is well known. Here two reels 80 of freshly processed film or paper are rotatably supported on a spindle 81 in side-by-side relation. Upon leaving the supply reels the strips of prints W pass upwardly over a guide roller 82, horizontally across the frame 10 and downwardly over a guide roller 82, and then over a glazing roller 83 where the emulsion surface of the prints may be wetted with a liquid which ywill produce a glossy surface on the prints when they against the drum surface by tension spring 87 acting on the arms. This roller may be latched in a raised position, as shown in Fig. l, by means of a latch indicated at 38 when the drier is to be threaded with a new strip of prints or is to be equipped with a print holding apron for handling individual prints. The strip of prints then passes around the drum surface to the pick-01f roller 89, at which point they are dried, and are then directed onto take-up reels 90. These take-up reels are driven by rest ing upon two rotatable rods 91 which are simultaneously driven by a motor 92. This typeof drive for the take-up reels produces a tendency drive for. the reels which readily accommodates for changes in the diameter of the roll of prints. 93 indicates a pair of radiant heaters which may be mounted on the supporting frame to produce a preliminary drying action onthe strip of prints if such is desirable or necessary. This drum drier can be used to dry individual prints if desired by merely equipping the drum with an endless apron which will hold the prints onto the drum surface during a partial rotation as is well known.

From the above description it will be appreciated that by constructing the drying drum so that its polished rim can be readily removed without disassembling the entire apparatus, the polished surface of the drum can be readily resurfaced while the apparatus can be kept in operation by substituting a new rim therefor. Likewise, this removable rim feature greatly simplifies the initial fabrication of the device since all surfaces of the water jacket are capable of being exposed to facilitate making the piping connections. In addition, cleaning of the water jacket is made possible. The novel water-tight seal construction we have devised for the removable rim not only produces a desired liquid sealing function but also produces a friction drive connection between the drum and rim so that the two parts move as one. By mounting the drum in a cantilever fashion on an opensided supporting frame the interchangeable rim feature of this drier drum is made practical. Furthermore, this type of drum mounting makes it easy to thread the drum from the end and makes it easy to read the temperature and adjust the thermostat dial without interference.

Although we have shown and described certain specific embodiments of our invention, we are fully aware that many modifications thereof are possible. Our invention, therefore, is not to be restricted except insofar as it is necessitated by the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. In a photographic print drier the combination of a supporting frame; a drum rotatably mounted on said frame; a cylindrical rim of heat conducting material of slightly larger diameter than said drum and in concentric relation therewith; means adjacent each end of said drum for holding said rim in concentric relation with said drum, for closing the ends of the space between the drum and said rim with a fluid-tight seal to form a fluid jacket around the periphery of said drum, and for connecting the rim in driving relation with said drum so that it will rotate therewith while allowing it to he slipped axially on and off the end thereof; said means including a selectively inflatable and deflatable tube of material having a relatively high coefficient of friction embracing each end of the drum and adapted to be expanded into fluid-tight and frictional driving contact with said rim and drum when inflated; and means for circulating a heated fluid through said fluid jacket.

2. In a photographic print drier the combination of a supporting frame; a drum member rotatably mounted on said frame; a cylindrical rim member of heat conducting material and of slightly larger diameter than said drum adapted to be slipped axially onto and off said drum in concentric relation therewith; radial flanges on one of said members adjacent each end thereof and substantially equal in length to the difference in radius of said members for holding the members in concentric relation when the rim is slipped onto said drum and constituting end walls for the space between the two, whereby a shallow water jacket is formed about said drum by the drum and rim peripheries and said radial flanges; means for selectively connecting the drum and rim together with a liquid-tight seal while providing a driving connection between the two and permitting the rim to be slipped axially on and off the end of the drum, said means including two inflatable and deflatable tubes, one carried by and encircling one of said members adjacent each end thereof and held against axial movement on said member by said radial flanges and adapted, when inflated, to frictionally connect the two members in driving relation; and means for circulating temperature controlled water through said water jacket while said drum is rotating.

3. In a photographic print drier the combination of a supporting frame; a drum rotatably mounted on said frame; a pair of like annular partitions extending circumferentially around and radially of the periphery of said drum adjacent each end thereof and each pair of partitions separated axially of the drum to form a trough between them extending circumferentially of the drum; a cylindrical rim of heat conductive material having an internal diameter allowing said rim to slip over and be supported by the periphery of said partitions whereby the space enclosed by the peripheries of said drum and rim along with said partitions form a water jacket; an inflatable rubber-like tube seated in each of said troughs adapted when inflated to provide a liquid-tight seal for each end of said water jacket and to frictionally connect the rim to said drum to move therewith, and when deflated to permit said rim to be slipped onto and off the end of said drum; and means for circulating temperature controlled water through said water jacket.

References Cited in the file of this patent UNITED STATES PATENTS 794,987 Kneuper July 18, 1905 2,504,025 Humason Apr. 11, 1950 2,582,365 Westphall Ian. 15, 1952 2,706,620 Graves Apr. 19, 1955 2,737,368 Blanchette et al. Mar. 6, 1956 2,827,312 Spencer Mar. 18, 1958 

